Isolated voltage regulator, method and power semiconductor reliability test apparatus

Abstract

The application discloses an isolated voltage stabilizing power supply, a method and a power semiconductor reliability test device. The isolated voltage stabilizing power supply is applied to the power semiconductor reliability test device. The isolated voltage stabilizing power supply comprises a program-controlled power supply, a current sampling circuit, a transformer and a controller. The program-controlled power supply is connected to a primary side of the transformer. A secondary side of the transformer is used for connecting a load. The current sampling circuit is connected to an input loop formed by the program-controlled power supply and the primary side of the transformer. The current sampling circuit is used for collecting an input current value of the primary side of the transformer and sending the input current value to the controller. The controller is used for obtaining an input voltage value of the primary side of the transformer according to the input current value and a fitting function. The program-controlled power supply is controlled according to the input voltage value to output a corresponding voltage, so that an output voltage of the secondary side of the transformer is a target output voltage. The fitting function is used for representing a corresponding relationship between the input current value and the input voltage value of the primary side of the transformer. The application can reduce the voltage stabilizing cost of the isolated voltage stabilizing power supply.

Description

Technical Field

[0001] This application relates to the field of power electronics technology, specifically to an isolated regulated power supply, a method, and a power semiconductor reliability testing device. Background Technology

[0002] Isolated power supplies are used in power electronic equipment and industrial control equipment to provide a stable output voltage to the load while achieving electrical isolation.

[0003] In related technologies, to improve the stability of the secondary output voltage of an isolated power supply, the secondary output voltage is typically detected, and the detection result is fed back to the primary control circuit to achieve voltage regulation control of the secondary output voltage. However, using a feedback method for voltage regulation control can easily increase the complexity of the power supply circuit and the hardware cost. Summary of the Invention

[0004] In view of this, this application provides an isolated regulated power supply, a method, and a power semiconductor reliability testing device, which can reduce the voltage regulation cost of the isolated regulated power supply.

[0005] To solve the above problems, the technical solution provided in this application is as follows: This application provides an isolated regulated power supply for use in power semiconductor reliability testing equipment. The isolated regulated power supply includes: a programmable power supply, a current sampling circuit, a transformer, and a controller. The programmable power supply is connected to the primary side of the transformer, and the secondary side of the transformer is used to connect to the load. The current sampling circuit is connected in the input loop formed by the programmable power supply and the primary side of the transformer. The current sampling circuit is used to collect the input current value of the primary side of the transformer and send it to the controller. The controller is used to obtain the input voltage value of the primary side of the transformer based on the input current value and a fitting function. The controller controls the programmable power supply to output a corresponding voltage based on the input voltage value, so that the output voltage of the secondary side of the transformer is the target output voltage. The fitting function is used to characterize the correspondence between the input current value and the input voltage value of the primary side of the transformer.

[0006] One possible implementation is that the current sampling circuit includes a sampling resistor and a controller for obtaining the input current value based on the voltage across the sampling resistor and the resistance value of the sampling resistor.

[0007] One possible implementation involves a controller that, during the commissioning phase of the isolated regulated power supply, controls the secondary side of the transformer to output multiple different output current values. While controlling the secondary side of the transformer to output different output current values, the controller adjusts the output voltage of the programmable power supply to keep the output voltage of the transformer secondary side at a preset output voltage. A fitting function is then established based on the primary side input current and primary side input voltage values ​​corresponding to each output current value.

[0008] One possible implementation involves a controller used during the commissioning phase of an isolated regulated power supply to control the output of a programmable power supply to maintain a constant input voltage; this constant input voltage is then used as the primary-side input voltage value.

[0009] One possible implementation of the isolated regulated power supply also includes a voltage sampling circuit; the voltage sampling circuit is connected to the primary side of the transformer; and a controller is used to acquire the primary side input voltage value corresponding to each output current value collected by the voltage sampling circuit during the process of controlling the secondary side of the transformer to output different output current values.

[0010] One possible implementation involves a controller that uses a linear fitting method to obtain fitting parameters based on the primary-side input current values ​​and corresponding primary-side input voltage values; and then establishes a fitting function based on the fitting parameters.

[0011] One possible implementation is that the load includes an isolated drive circuit for a power semiconductor device; an isolated regulated power supply is used to power the isolated drive circuit.

[0012] This application also provides a control method for an isolated regulated power supply, applied to a power semiconductor reliability testing equipment. The isolated regulated power supply includes: a programmable power supply, a current sampling circuit, a transformer, and a controller; the programmable power supply is connected to the primary side of the transformer, and the secondary side of the transformer is used to connect to the load; the current sampling circuit is connected in the input loop formed by the programmable power supply and the primary side of the transformer; the method includes: obtaining the input current value of the primary side of the transformer based on the sampling signal output by the current sampling circuit; obtaining the input voltage value of the primary side of the transformer based on a fitting function and the input current value; wherein, the fitting function is used to characterize the correspondence between the input current value and the input voltage value of the primary side of the transformer; controlling the programmable power supply to output a corresponding voltage based on the input voltage value, so that the output voltage of the secondary side of the transformer is the target output voltage.

[0013] This application also provides a power semiconductor reliability testing device, including an isolated regulated power supply and an isolated drive circuit provided by any of the above implementations; the output terminal of the isolated regulated power supply is connected to the isolated drive circuit; the isolated regulated power supply is used to supply power to the isolated drive circuit, and the isolated drive circuit is used to output drive signals to the power semiconductor device under test.

[0014] One possible implementation is that the power semiconductor reliability testing equipment includes multiple test stations; each test station corresponds to at least one power semiconductor device to be tested; each test station is equipped with an isolated regulated power supply and an isolated drive circuit.

[0015] The isolated voltage regulator provided in this application acquires the input current value of the primary side of the transformer through a current sampling circuit, determines the corresponding primary side input voltage value based on a fitting function, and controls the programmable power supply to output the corresponding voltage. This allows the programmable power supply to adaptively adjust the primary side input voltage according to changes in the secondary side load, thereby maintaining the secondary side output voltage of the transformer at the target output voltage. This achieves voltage regulation control of the isolated power supply without the need for secondary side voltage feedback and high-voltage isolation feedback circuits, which helps reduce the circuit complexity and hardware cost of the isolated voltage regulator; it also helps reduce the overall cost of power semiconductor reliability testing equipment and improves its engineering application value. Attached Figure Description

[0016] Figure 1 A schematic diagram of an isolated regulated power supply provided in an embodiment of this application; Figure 2 A schematic diagram of another isolated regulated power supply provided in an embodiment of this application; Figure 3 A flowchart illustrating a control method for an isolated regulated power supply provided in an embodiment of this application; Figure 4 This is a schematic diagram of a power semiconductor reliability testing device provided in an embodiment of this application. Detailed Implementation

[0017] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the embodiments of this application will be further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0018] Power semiconductor reliability testing equipment is used in the reliability testing of power semiconductor devices. It provides drive power to the power semiconductor device under test, applying different voltage, current, or frequency stresses to achieve aging tests. In power semiconductor reliability testing equipment, to ensure electrical isolation between the primary and secondary sides, an isolated regulated power supply is typically used to power the isolated drive circuit.

[0019] In related technologies, to improve the stability of the output voltage on the secondary side of an isolated regulated power supply, the output voltage on the secondary side of the transformer is typically detected, and the detection result is fed back to the primary side control circuit. The primary side input voltage is then adjusted based on the secondary side output voltage to achieve voltage regulation control of the secondary side output voltage. Since electrical isolation needs to be maintained between the primary and secondary sides, a high-voltage isolation feedback circuit is usually required, such as using optocoupler isolation devices or analog isolation devices to achieve secondary side output voltage feedback.

[0020] However, using isolation feedback for voltage regulation requires adding a high-voltage isolation feedback circuit and corresponding control circuit, which easily increases the circuit complexity and hardware cost of the isolated voltage regulator. Especially when power semiconductor reliability testing equipment has multiple test stations and requires a large number of isolated voltage regulators, the overall cost increases further, making it difficult to balance voltage regulation performance and cost requirements.

[0021] In view of this, this application provides an isolated regulated power supply for use in power semiconductor reliability testing equipment. It can determine the corresponding primary input voltage value based on the primary input current value of the transformer, and adjust the corresponding voltage output of the programmable power supply according to the input voltage value to achieve voltage regulation control of the secondary output voltage of the transformer. This improves the stability of the secondary output voltage while reducing the voltage regulation cost of the isolated regulated power supply.

[0022] See Figure 1 The figure is a schematic diagram of an isolated regulated power supply provided in an embodiment of this application.

[0023] The isolated regulated power supply provided in this application embodiment is applied to power semiconductor reliability testing equipment. The isolated regulated power supply includes a transformer 10, a programmable power supply U, a controller 20, and a current sampling circuit 30.

[0024] The programmable power supply U is connected to the primary side of transformer 10, and the secondary side of transformer 10 is used to connect the load.

[0025] The current sampling circuit 30 is connected to the input circuit formed by the programmable power supply U and the primary side of the transformer 10. It is used to collect the input current value of the primary side of the transformer 10 and send it to the controller 20.

[0026] The programmable power supply U is used to output the corresponding input voltage to the primary side of transformer 10; transformer 10 is used to achieve electrical isolation between the primary and secondary sides, convert the primary input voltage into the secondary output voltage, and supply power to the load.

[0027] The controller 20 is used to obtain the input voltage value of the primary side of the transformer 10 based on the input current value and the fitting function; and to control the programmable power supply U to output the corresponding voltage based on the input voltage value, so that the output voltage of the secondary side of the transformer 10 is the target output voltage. The fitting function is used to characterize the correspondence between the input current value and the input voltage value of the primary side of the transformer 10.

[0028] During the operation of the programmable power supply U, when the secondary load changes, the input current on the primary side of transformer 10 also changes accordingly. Therefore, this application can obtain the input current value on the primary side of transformer 10 and determine the primary input voltage value corresponding to the current input current value based on a pre-established fitting function. The fitting function characterizes the correspondence between the input current value and the input voltage value on the primary side of the transformer; different input current values ​​correspond to different input voltage values.

[0029] After obtaining the corresponding input voltage value, this application can control the programmable power supply to output the corresponding voltage, so that the primary side of transformer 10 obtains the corresponding input voltage. Since the primary side input voltage can be adjusted according to the change of the primary side input current, even if the secondary side load changes, the secondary side of transformer 10 can maintain the target output voltage, realizing the voltage regulation control of the secondary side output voltage without the need for real-time feedback of the secondary side output voltage.

[0030] It should be noted that the fitting function can be pre-established during the debugging phase of the programmable power supply circuit and stored in the control program. During normal operation of the programmable power supply U, the input current value of the primary side of transformer 10 is obtained, and the corresponding input voltage value can be quickly determined according to the fitting function. This allows the programmable power supply U to output the corresponding voltage, thereby achieving stable control of the secondary output voltage.

[0031] This application does not specifically limit the composition of the primary and secondary circuits of the transformer 10. For example, the primary side of the transformer 10 can be connected to a power conversion circuit, which may include at least one switching device, an energy storage device, and other circuits for voltage conversion or energy transfer; the secondary side of the transformer 10 can be connected to a rectifier circuit, a filter circuit, and a load, and the rectifier circuit may include a half-wave rectifier circuit, a full-wave rectifier circuit, a bridge rectifier circuit, or other rectifier circuits. This application does not specifically limit these aspects.

[0032] For ease of understanding, Figure 1 This paper illustrates one implementation of a power conversion circuit connected to the primary side of transformer 10, and a bridge rectifier circuit and a filter circuit connected to the secondary side of transformer 10.

[0033] This application does not specifically limit the specific connection method between the programmable power supply U and the primary side of the transformer 10. Figure 1 The illustrations shown are for illustrative purposes only and do not constitute a limitation of this application.

[0034] The isolated voltage regulator provided in this application acquires the input current value of the primary side of the transformer through a current sampling circuit, determines the corresponding primary side input voltage value based on a fitting function, and controls the programmable power supply to output the corresponding voltage. This allows the programmable power supply to adaptively adjust the primary side input voltage according to changes in the secondary side load, thereby maintaining the secondary side output voltage of the transformer at the target output voltage. This achieves voltage regulation control of the isolated power supply without the need for secondary side voltage feedback and high-voltage isolation feedback circuits, which helps reduce the circuit complexity and hardware cost of the isolated voltage regulator; it also helps reduce the overall cost of power semiconductor reliability testing equipment and improves its engineering application value.

[0035] See Figure 2 The figure is a schematic diagram of another isolated regulated power supply provided in an embodiment of this application.

[0036] One possible implementation is that the current sampling circuit provided in this application embodiment may include a sampling resistor R.

[0037] The controller 20 is used to obtain the input current value based on the voltage across the sampling resistor R and the resistance value of the sampling resistor R.

[0038] The sampling resistor R can be connected in series in the input circuit of the primary side of transformer 10. The current flowing into the primary side of transformer 10 flows through the sampling resistor R, forming a corresponding voltage across the sampling resistor R. The controller 20 collects the voltage across the sampling resistor R and calculates the input current value of the primary side of transformer 10 based on the resistance value of the sampling resistor R.

[0039] For example, if the voltage across the sampling resistor R is VR and the resistance of the sampling resistor is R, then the primary input current value can be determined based on the ratio of VR to R.

[0040] The value of the sampling resistor R can be set according to factors such as the primary input current range, sampling accuracy, and sampling loss. This application embodiment does not impose specific limitations on this.

[0041] This embodiment of the application sets a sampling resistor on the primary side of the transformer, and obtains the input current value of the primary side of the transformer based on the voltage across the sampling resistor and the resistance value of the sampling resistor. This can convert the input current into a voltage signal that is easy to collect and process, thereby achieving accurate acquisition of the input current and reducing the cost of primary side current detection.

[0042] In one possible implementation, the isolated voltage regulator provided in this application embodiment includes a controller that, during the commissioning phase of the isolated voltage regulator, controls the secondary side of the transformer to output multiple different output current values; while controlling the secondary side of the transformer to output different output current values, the controller adjusts the output voltage of the programmable power supply so that the output voltage of the secondary side of the transformer is kept at a preset output voltage; and a fitting function is established based on the primary side input current value and primary side input voltage value corresponding to each output current value.

[0043] Before the isolated voltage regulator is put into normal operation, the controller can first debug the isolated voltage regulator to establish the correspondence between the input current value and the input voltage value of the primary side of the transformer.

[0044] During commissioning, an adjustable load can be connected to the secondary side of the transformer to replace the actual load. The controller can control the adjustable load to be in multiple different load states, so that the secondary side of the transformer outputs multiple different output current values.

[0045] Multiple different output current values ​​can be selected within the preset load range of the transformer secondary side. The preset load range can be the entire load range of the transformer secondary side, or a portion of the load range corresponding to the normal operation of the isolated regulated power supply.

[0046] This application does not specifically limit the number of output current values ​​or the current interval between adjacent output current values. These can be determined based on a preset load range, fitting accuracy, and debugging efficiency. Multiple different output current values ​​may include the output current value corresponding to zero load, the output current value corresponding to full load, and the output current value corresponding to at least one intermediate load. Alternatively, they may only include multiple non-zero output current values ​​within a preset load range. The more output current values ​​there are, the better the obtained data reflects the correspondence between the primary-side input current value and the primary-side input voltage value. Each output current value can be selected with the same current interval or with different current intervals.

[0047] For example, it can output 50mA, 100mA, 150mA, and so on until the output current value corresponding to full load is reached.

[0048] During the process of different output current values ​​on the secondary side of the transformer, the controller synchronously adjusts the output voltage of the programmable power supply to keep the output voltage of the secondary side of the transformer at the preset output voltage. When the output voltage of the secondary side of the transformer stabilizes at the preset output voltage, the controller acquires the primary side input current value and the primary side input voltage value corresponding to the current output current value. Therefore, by changing the output current value of the secondary side of the transformer in the above manner, multiple sets of corresponding primary side input current values ​​and primary side input voltage values ​​can be obtained.

[0049] The preset output voltage is the secondary output voltage that needs to be maintained when obtaining the fitted function, and can be determined based on the target output voltage of the isolated regulated power supply. For example, the preset output voltage can be 60V, but this embodiment does not specifically limit it.

[0050] After acquiring data corresponding to multiple output current values, the controller establishes a fitting function based on multiple sets of primary-side input current values ​​and corresponding primary-side input voltage values. This fitting function is stored for use when the isolated regulated power supply is operating normally. The fitting function characterizes the relationship between the primary-side input current value and the primary-side input voltage value when the transformer secondary-side output voltage remains at the preset output voltage.

[0051] This application embodiment adjusts the output voltage of the programmable power supply under multiple different secondary output current values ​​to keep the secondary output voltage of the transformer at a preset output voltage. This allows the primary input current and primary input voltage values ​​corresponding to multiple load states to be obtained. In this way, a fitting function that reflects the correspondence between load changes and primary input parameters can be established, providing a control basis for determining the primary input voltage value based on the primary input current value when the isolated voltage regulator is operating normally, thereby improving the accuracy of voltage regulation control.

[0052] In one possible implementation, in the isolated regulated power supply provided in this application embodiment, the controller is used to control the programmable power supply to output a constant input voltage during the commissioning phase of the isolated regulated power supply; and to use the constant input voltage as the primary side input voltage value.

[0053] Specifically, in obtaining the fitted function, the controller can pre-control the programmable power supply to output a set constant input voltage, and the constant input voltage output by the programmable power supply can be used as the primary-side input voltage value corresponding to the current operating condition. In this implementation, the primary-side input voltage is a known control quantity, so there is no need to set up a separate voltage sampling circuit to collect the primary-side input voltage.

[0054] One possible implementation is that this application can control the programmable power supply to output multiple different constant input voltages, and obtain the corresponding primary-side input current value under each constant input voltage, thereby obtaining multiple sets of primary-side input current values ​​and primary-side input voltage values. The specific value of the constant input voltage and its adjustment interval can be determined according to the input voltage range of the transformer and the target output voltage of the secondary side.

[0055] This application embodiment uses the constant input voltage output by the programmable power supply as the primary input voltage value, which can reduce the sampling stage of the primary input voltage and the corresponding voltage sampling device, simplify the process of obtaining fitting data, and reduce the hardware cost of the isolated regulated power supply.

[0056] In one possible implementation, the isolated regulated power supply provided in this application embodiment may further include a voltage sampling circuit.

[0057] The voltage sampling circuit is connected to the primary side of the transformer.

[0058] The controller is used to acquire the primary input voltage value corresponding to each output current value collected by the voltage sampling circuit during the process of controlling the secondary side of the transformer to output different output current values.

[0059] The voltage sampling circuit can be connected to the input terminal of the primary side of the transformer to collect the actual input voltage received by the primary side. During the process of adjusting the secondary output current and correspondingly adjusting the output voltage of the programmable power supply, the voltage sampling circuit can obtain the actual primary input voltage value corresponding to each output current value.

[0060] The voltage sampling circuit may include at least one of a voltage divider circuit, an isolated sampling circuit, or an analog-to-digital converter circuit. The specific structure of the voltage sampling circuit can be determined based on the primary input voltage range and sampling accuracy; this application does not impose specific limitations on this aspect.

[0061] Since there may be device voltage drop, line voltage drop, or output error between the command output voltage of the programmable power supply and the actual input voltage received by the primary side of the transformer, the embodiments of this application obtain the actual primary side input voltage value through a voltage sampling circuit, which can make the established fitting function more accurately reflect the actual working state of the primary side of the transformer.

[0062] This application embodiment acquires the actual primary-side input voltage value through a voltage sampling circuit, which can reduce the impact of programmable power supply output error and line voltage drop on the fitting results, improve the accuracy of the fitting function, and thus further improve the voltage regulation accuracy of the isolated regulated power supply.

[0063] In one possible implementation, the isolated regulated power supply provided in this application embodiment includes a controller that uses a linear fitting method to obtain fitting parameters based on each primary-side input current value and the corresponding primary-side input voltage value; and establishes a fitting function based on the fitting parameters.

[0064] Specifically, the controller can use the primary-side input current value as the independent variable and the corresponding primary-side input voltage value as the dependent variable, and perform linear fitting on the obtained multiple sets of data to obtain the fitting parameters.

[0065] Linear fitting can be performed using the least squares method or other fitting methods that can obtain linear relationship parameters; this application does not specifically limit this method.

[0066] One possible implementation is that the fitting function can be expressed as: U IN =k×I IN +b.

[0067] During the debugging phase, U IN I represents the primary input voltage value of the transformer. IN This represents the primary input current value of the transformer; in practical applications, U... INI represents the input voltage value on the primary side of the transformer. IN This indicates the input current value on the primary side of the transformer.

[0068] k and b are fitting parameters obtained from multiple sets of primary-side input current and primary-side input voltage values. The fitting parameter k is used to characterize the magnitude of the change in primary-side input voltage value with the primary-side input current value, and the fitting parameter b is used to characterize the intercept of the fitting function.

[0069] After obtaining the fitting parameters, the controller can establish a fitting function based on the fitting parameters and store the fitting function so that it can be called when the isolated regulated power supply is working normally. During the normal operation of the isolated regulated power supply, after obtaining the current primary-side input current value, the primary-side input current value can be substituted into the fitting function to calculate the corresponding primary-side input voltage value.

[0070] One possible implementation is that the correspondence between the primary-side input current and the primary-side input voltage may differ under different target output voltages. Therefore, this application can also perform linear fitting for different target output voltages to obtain multiple fitting functions. When the target output voltage changes, the fitting function corresponding to the current target output voltage can be selected to determine the primary-side input voltage value.

[0071] This application embodiment converts discrete debugging data into a functional relationship that is easy to store and recall by linearly fitting multiple sets of primary-side input current values ​​and corresponding primary-side input voltage values. When the isolated regulated power supply is working normally, the corresponding primary-side input voltage value can be quickly obtained by substituting the primary-side input current value into the fitting function. The computational load is small, which facilitates real-time control and can meet the voltage regulation requirements when the secondary-side load changes.

[0072] In one possible implementation, the isolated regulated power supply provided in this application embodiment may include an isolated drive circuit for a power semiconductor device as its load. The isolated regulated power supply is used to power the isolated drive circuit.

[0073] An isolated driver circuit is used to output a drive signal to the power semiconductor device under test to control its on / off state. During operation, the isolated driver circuit requires a stable supply voltage to ensure the stability of the output drive signal.

[0074] When the load corresponding to the isolated drive circuit changes, the controller can adjust the output voltage of the programmable power supply according to the input current value of the transformer primary side and the fitting function, so that the output voltage of the transformer secondary side is kept at the target output voltage, thereby enabling the isolated drive circuit to obtain a stable power supply voltage.

[0075] The embodiments of this application do not specifically limit the specific structure of the isolation drive circuit. The isolation drive circuit may include a drive chip, a drive resistor, a protection circuit, and other circuits for driving power semiconductor devices, and the embodiments of this application do not specifically limit these components.

[0076] This application applies an isolated regulated power supply to the isolated drive circuit of a power semiconductor device, which can maintain a stable supply voltage when the load of the isolated drive circuit changes. This helps to ensure a stable output drive signal from the isolated drive circuit and improves the stability of the reliability testing process for power semiconductor devices.

[0077] Based on the isolated voltage regulator provided in the above embodiments, this application also provides a control method for the isolated voltage regulator.

[0078] See Figure 3 The figure is a flowchart of a control method for an isolated regulated power supply provided in an embodiment of this application.

[0079] The control method for the isolated regulated power supply provided in this application embodiment is applied to a power semiconductor reliability testing equipment. The isolated regulated power supply includes a programmable power supply, a current sampling circuit, a transformer, and a controller. The programmable power supply is connected to the primary side of the transformer, and the secondary side of the transformer is used to connect the load. The current sampling circuit is connected to the input circuit formed by the programmable power supply and the primary side of the transformer.

[0080] The control method provided in this application includes: S101: Obtain the input current value of the primary side of the transformer based on the sampling signal output by the current sampling circuit.

[0081] S102: Obtain the input voltage value of the primary side of the transformer based on the fitting function and the input current value.

[0082] The fitting function is used to characterize the correspondence between the input current value and the input voltage value of the transformer primary side.

[0083] S103: Controls the output voltage of the programmable power supply according to the input voltage value, so that the output voltage of the transformer secondary side is the target output voltage.

[0084] The control method provided in this application embodiment controls the input voltage of the programmable power supply based on the primary input current value collected by the current sampling circuit and a pre-established fitting function. This method can achieve voltage regulation control of the secondary output voltage without needing to obtain the secondary output voltage, which helps to reduce the circuit complexity and hardware cost of the isolated voltage regulator.

[0085] Based on the isolated regulated power supply provided in the above embodiments, this application also provides a power semiconductor reliability testing device.

[0086] See Figure 4 The figure is a schematic diagram of a power semiconductor reliability testing device provided in an embodiment of this application.

[0087] The power semiconductor reliability testing equipment provided in this application includes an isolated regulated power supply 100 and an isolated drive circuit 200.

[0088] The output terminal of the isolated regulated power supply 100 is connected to the isolated drive circuit 200.

[0089] The isolated regulated power supply 100 is used to supply power to the isolated drive circuit 200, which is used to output drive signals to the power semiconductor device under test in order to control the power semiconductor device under test to perform reliability testing.

[0090] Power semiconductor reliability testing equipment can apply different driving voltages, driving frequencies, or driving sequences to the power semiconductor device under test according to the testing requirements, so as to simulate the operating state under different working conditions and complete the reliability test.

[0091] During the test, when the load corresponding to the isolation drive circuit 200 changes, the isolation regulated power supply 100 adjusts the output voltage of the programmable power supply according to the input current value of the transformer primary side and the fitting function, so that the isolation drive circuit 200 always obtains a stable power supply voltage, thereby ensuring that the isolation drive circuit 200 outputs a stable drive signal.

[0092] This application embodiment sets up an isolated regulated power supply and an isolated drive circuit in the power semiconductor reliability testing equipment. The isolated regulated power supply provides a stable power supply to the isolated drive circuit, which can ensure that the isolated drive circuit outputs a stable drive signal, thereby improving the stability of power semiconductor reliability testing and the consistency of test results.

[0093] One possible implementation is that the power semiconductor reliability testing equipment provided in this application embodiment includes multiple testing stations.

[0094] Each test station corresponds to at least one power semiconductor device to be tested; Each test station is equipped with an isolated regulated power supply and an isolated drive circuit.

[0095] Power semiconductor reliability testing equipment can include multiple independent test stations. The isolated regulated power supply of each test station independently adjusts its output voltage according to the load change of the corresponding test station, so that the corresponding isolated drive circuit of each test station can obtain a stable power supply voltage.

[0096] The embodiments of this application do not specifically limit the number of test stations. For example, a power semiconductor reliability testing equipment may include dozens, hundreds, or even more test stations, and the embodiments of this application do not specifically limit this.

[0097] This application embodiment configures isolated regulated power supplies at multiple test stations, enabling each test station to independently complete voltage regulation control. This achieves multi-channel isolated regulated power supply without the need for secondary high-voltage isolation feedback circuits, which helps reduce the overall hardware cost of multi-station power semiconductor reliability testing equipment and improves the system's engineering application capabilities.

[0098] Based on the control method for isolated regulated power supplies provided in the above embodiments, this application also provides a controller.

[0099] The controller provided in this application embodiment is used to execute the control method of the isolated regulated power supply provided in any of the above embodiments.

[0100] The controller may include a processor and a memory. The memory stores programs or instructions, and when the processor executes the programs or instructions, it implements the control method for the isolated regulated power supply described above. The controller may be a microcontroller unit, a digital signal processor, a field-programmable gate array, or other devices with data acquisition, processing, and control functions.

[0101] The controller provided in this application embodiment can determine the corresponding primary input voltage value based on the input current value of the transformer primary side and the fitting function by executing the control method of the isolated voltage regulator described above. It can then adjust the output voltage of the programmable power supply according to the input voltage value, so that the output voltage of the transformer secondary side is maintained at the target output voltage. This can reduce the complexity of the programmable power supply circuit and the hardware cost.

[0102] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0103] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An isolated regulated power supply, characterized in that, The isolated regulated power supply, used in power semiconductor reliability testing equipment, includes: a programmable power supply, a current sampling circuit, a transformer, and a controller; The programmable power supply is connected to the primary side of the transformer, and the secondary side of the transformer is used to connect the load. The current sampling circuit is connected to the input circuit formed by the programmable power supply and the primary side of the transformer; the current sampling circuit is used to collect the input current value of the primary side of the transformer and send it to the controller. The controller is configured to obtain the input voltage value of the primary side of the transformer based on the input current value and the fitting function; and control the programmable power supply to output a corresponding voltage based on the input voltage value, so that the output voltage of the secondary side of the transformer is the target output voltage. The fitting function is used to characterize the correspondence between the input current value and the input voltage value on the primary side of the transformer.

2. The power supply according to claim 1, characterized in that, The current sampling circuit includes a sampling resistor; The controller is used to obtain the input current value based on the voltage across the sampling resistor and the resistance value of the sampling resistor.

3. The power supply according to claim 1, characterized in that, The controller is used to control the secondary side of the transformer to output multiple different output current values ​​during the commissioning phase of the isolated regulated power supply; while controlling the secondary side of the transformer to output different output current values, the controller adjusts the output voltage of the programmable power supply so that the output voltage of the secondary side of the transformer is kept at a preset output voltage; and establishes the fitting function based on the primary side input current value and primary side input voltage value corresponding to each output current value.

4. The power supply according to claim 3, characterized in that, The controller is used to control the programmable power supply to output a constant input voltage during the commissioning phase of the isolated regulated power supply; and to use the constant input voltage as the primary side input voltage value.

5. The power supply according to claim 3, characterized in that, The isolated regulated power supply also includes a voltage sampling circuit; The voltage sampling circuit is connected to the primary side of the transformer; The controller is used to acquire the primary input voltage value corresponding to each output current value collected by the voltage sampling circuit during the process of controlling the secondary side of the transformer to output different output current values.

6. The power supply according to claim 3, characterized in that, The controller is used to obtain fitting parameters based on each primary-side input current value and the corresponding primary-side input voltage value using a linear fitting method; and to establish the fitting function based on the fitting parameters.

7. The power supply according to any one of claims 1-6, characterized in that, The load includes an isolated drive circuit for a power semiconductor device; The isolated regulated power supply is used to power the isolated drive circuit.

8. A control method for an isolated regulated power supply, characterized in that, An isolated regulated power supply is used in power semiconductor reliability testing equipment. It includes a programmable power supply, a current sampling circuit, a transformer, and a controller. The programmable power supply is connected to the primary winding of the transformer, and the secondary winding of the transformer is used to connect to a load. The current sampling circuit is connected to the input circuit formed by the programmable power supply and the primary winding of the transformer. The method includes: The input current value of the primary side of the transformer is obtained based on the sampling signal output by the current sampling circuit; The input voltage value of the primary side of the transformer is obtained based on the fitting function and the input current value; wherein, the fitting function is used to characterize the correspondence between the input current value and the input voltage value of the primary side of the transformer. The programmable power supply is controlled to output a corresponding voltage based on the input voltage value, so that the output voltage of the secondary side of the transformer is the target output voltage.

9. A power semiconductor reliability testing device, characterized in that, Includes the isolated regulated power supply and isolated drive circuit as described in any one of claims 1-7; The output terminal of the isolated regulated power supply is connected to the isolated drive circuit; The isolated regulated power supply is used to power the isolated drive circuit, which is used to output drive signals to the power semiconductor device under test.

10. The device according to claim 9, characterized in that, The power semiconductor reliability testing equipment includes multiple testing stations; Each test station corresponds to at least one power semiconductor device to be tested; Each test station is equipped with the isolated regulated power supply and the isolated drive circuit.

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